<template>
  <div class="xtx-numbox">
    <div class="label" v-if="label">{{ label }}</div>
    <div class="numbox">
      <a @click="changeNum(-1)" href="javascript:;">-</a>
      <input type="text" readonly :value="modelValue">
      <a @click="changeNum(1)" href="javascript:;">+</a>
    </div>
  </div>
</template>
<script  setup >
import { useVModel } from '@vueuse/core'

const props = defineProps({
  label: {
    type: String,
    default: ''
  },
  modelValue: {
    type: Number,
    default: 1
  },
  // 最小值，最大值
  min: {
    type: Number,
    default: 1
  },
  max: {
    type: Number,
    default: 10
  }
})

const emit = defineEmits(["update:modelValue", "change"])

// 1. 绑定按钮点击事件  -按钮 +按钮 触发同一个事件，同一个函数
// 2. 使用vueuse的useVModel做数据绑定,修改 count 通知父组件更新
const count = useVModel(props, 'modelValue', emit)
const changeNum = (step) => {
  // 3. 得到将要改变的值，如果值不合法终止程序
  const newValue = count.value + step
  if (newValue < props.min || newValue > props.max) return
  // 4. 正常改值即可
  count.value = newValue
  // 5. 提供change事件
  emit('change', newValue)
}

</script>
<style scoped lang="less">
.xtx-numbox {
  display: flex;
  align-items: center;

  .label {
    width: 60px;
    color: #999;
    padding-left: 10px;
  }

  .numbox {
    width: 120px;
    height: 30px;
    border: 1px solid #e4e4e4;
    display: flex;

    >a {
      width: 29px;
      line-height: 28px;
      text-align: center;
      background: #f8f8f8;
      font-size: 16px;
      color: #666;

      &:first-of-type {
        border-right: 1px solid #e4e4e4;
      }

      &:last-of-type {
        border-left: 1px solid #e4e4e4;
      }
    }

    >input {
      width: 60px;
      padding: 0 5px;
      text-align: center;
      color: #666;
    }
  }
}
</style>
